In this study, a multispectral imaging system with an RGB camera and a multichannel LED system was investigated. Firstly, it was proposed to generalize a previous method to optimize the flexible combinations of no more than three LED channels in each light source. The systems of 6-channel, 9-channel, and 12-channel were obtained, and their performances were compared with a typical 3-channel system under D65. Subsequently, the systems using single LED channels as light sources were explored. Two different methods (single-light and single-channel) were developed by selecting different numbers of the optimal lights or system channels. It was found the single-channel system outperformed the system using combined LED channels in terms of the spectral reconstruction accuracy. However, it should be noted the single-channel system required significantly more captures than the method by combining three channels in a light.